US1818770A - Process of dispersing carbon - Google Patents

Description

Patented Aug. 11,. 1931 UNITED STATES PATENT orrlcs I WILLIAM F. TULEY, N 'IJ'TLEY. N EW JERSEY, ASSIGNOR TO THE NAUGATZUGK CHEML' GAL COMPANY, OF NAUGATUCK, CONNECTICUT, A CORPORATION OF CONNECTICUT l PROCESS OF DISPERSING CARBON No Drawing.

This invention relatesoto the art of dispersing carbon in a polar liquid. v

Due to the inherent difiiculty of wetting finely divided carbon it has been necessary heretofore in the preparation of dispersions to grind the carbon in a ball mill in the presence of Water and to employ stabilizing agents ing carbon which does not involve long grind mg or the use of stabilizing colloids. Another object of this invention is the production of finely divided carbon in the form of a paste or dry powder which will be dispersed when added to a polar dispersing medium.

, Other objects and advantages of the present 30 invention will appear in the following detailed description.

In practicing this invention, parts of carbon black is made into a paste with 70 parts of water in which one partof sodium sulphite has been dissolved. Preferably this paste is heated for l'hr. at 100"-C. When the paste isadded to a quantity of water or alcohol it is dispersed immediately.

.The proportion of water to carbon black may be varied without limit except that sufficient water must be provided to wet the carbon. The quantity of sodium sulphite may be varied within wide limits such as from about 1%- -10% of sodium sulphite based on the carbon. strength of sulphite solution may be varied by the addition of more or less water thereby I giving the process universal applicability. The carbon employed may be in any finely divided' form such as lamp black, bone charcoal, carbon black or any of the various forms of vegetable charcoals. In the place of sodium sulphite, the sulphites of any of the alkali metals or of ammonia may be used or equivalent amounts of alkali and sulphur dioxide may be added to Water to form the sulphite in solution.

Adispersible dry powder may be prepared as follows: 10 parts of carbon black may be mixed with 100 parts of water containing It is obviousv that the- Application filed November 9, 1929.. Serial No. 406,174.

1 part of sodium sulphite. The mixture may be heated at its boiling'tem erature for 1 hr The carbon black is then lteredout-and may be washed with fresh water, if desired, toremove the'excess of sulphite salt. Dis- 55 'persions may be prepared from the carbon black immediately after filtration or the carbon may be dried in the open air at ordinarytemperatures, if desired. Such a dry powder will disperse immediately when added to 00 Water or alcohol or other polar liquid medium. In carrying out this process the various kinds of finely divided carbon and the various substitutes for sodium sulphite above mentioned may beemployed.

The time and temperature of heating are without limit inasmuch as the action will proceed at ordinary room temperatures overa long period of time. The o timum time and temperature appears to be eating the mixture at the boiling temperature for appromR mately 15 minutes.

The dispersed carbon produced according to this process may be used in the manufacture of inks, water paints, or may be added to dispersed rubber or to other substances suspended in polar liquids such as water or 4 alcohol. v

Having described the invention in detail by way of illustration only, other modifications in the details of the process being obvious to one skilled in the art, the invention is now defined by the following claims.

Having thus described my invention, what I claim and desire to protect by Letters Patcut is:

1. In the art of dispersing carbon the steps of: mixing finely divided carbon with a solu- 2 rere ro dium sulpbite, potassium sulpbite, ammonium sulphite dissolved therein.

e. The method of dispersing carbon which consists in mixing finely divided carbon with a solution of sodium sulphite in Water.

5 5. A dispersible carbon which comprises a dried mixture of finely divided carbon and an alkali sulpliite and a polar dispersing medium. I

6. A dispersible carbon which comprises a dried mixture of finely divided carbon and an alkali sulpbite dissolved in a polar dispersing medium. I

7. In the art of dispersing carbon, the steps of mixing finely divided carbon with a so- 15 lution of an alkali sulphite in a polar dispersing medium, heating to boiling for at least fifteen minutes, and adding an excess of polar dispersing medium.

Signed at Passaic, county of Passaic, State or" New Jersey, this 26th day of October,

WILLIAM F. TUJLEY.